Leaf spring arrangement for automotive vehicle

ABSTRACT

A suspension spring arrangement for a vehicle having an upper elongated spring leaf ( 12 ) and a lower elongated spring leaf ( 14 ) with an upper elongated spring leaf ( 12 ) is provided with a slot ( 22 ) and a lower elongated spring leaf ( 14 ) is provided with a protuberance ( 24 ). When the upper and lower spring leafs ( 12, 14 ) are joined to one another, the protuberance ( 24 ) is accommodated within the slot ( 22 ) so as to prevent lateral displacement of the upper and lower spring leafs ( 12, 14 ) with respect to each other. Pounding and squeaking noises are prevented by the installation of a polymeric insert between the slot and the protuberance. The slot ( 22 ) and the protuberance ( 24 ) are configured in accordance with square, rectangular, and/or circular shapes, depending upon the particular application. A protuberance ( 24 ) and a slot ( 22 ) can be provided at each end of the suspension spring arrangement.

REFERENCE TO OTHER APPLICATION(S)

This application has been filed in the United States Patent andTrademark Office under 35 U.S.C. §371 based on International ApplicationNo. PCT/US99/23228 having an international filing date of Oct. 5, 1999and claiming a priority date of Oct. 7, 1998 based on Mexican Serial No.9808284. The International Application was published pursuant to thePatent Cooperation Treaty under International Publication No. WO00/20774 on Apr. 13, 2000 (International Publication Date).

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to springs used in automotivesuspension systems, and more particularly, to springs for use in therear suspension system of a vehicle.

2. Description of the Related Art

Springs that are presently in use in the suspension systems of vehiclesare formed of two parallel elongated sheets, or leafs, manufactured ofspring steel, such as SAE 5160, 6150, JSAE SUP 9, and are of the typethat are centrally joined by a bolt or a retaining clamp that isinstalled near one of the ends of the spring. The bolt functions to keepthe two spring leafs in joined condition, while the retaining clampavoids the spring leafs from becoming laterally displaced with respectto each other, whereupon the ability of the springs to support thevehicle would be diminished. In addition, such lateral displacement ofthe springs may result in one of the spring leafs hitting a part of thevehicle, such as a hose or the gas tank, creating a dangerous conditionduring the use of the vehicle. Placement of the retaining clamp iseffected upon fixing same with a rivet to one of the spring leafs,placing thereon a series of inserts, and closing the rivet with the useof a press or a hammer or mallet. Clearly, the installation of theretaining clamp is a labor intensive operation that requires adherenceto dimensional and tolerance specifications.

In view of the foregoing, it is an object of this invention to eliminatethe use of a retaining clamp for maintaining the lateral edges of twospring leafs parallel and in alignment.

It is also an object of this invention to eliminate the need for aretaining clamp while nevertheless achieving a comfortable ride in thevehicle as the vehicle is operated over holes and bumps.

It is another object of this invention to provide a spring havingresistance, capacity, and durability characteristics that remain similarto those of known springs.

It is still another object of this invention to provide a springarrangement that affords savings in labor and material by eliminatingthe need for a conventional retaining clamp.

SUMMARY OF THE INVENTION

The foregoing and other objects are achieved by this invention whichprovides, in accordance with a first apparatus aspect thereof, asuspension spring arrangement for a vehicle. The suspension springarrangement is of the type having an upper elongated spring leaf, alower elongated spring leaf, and clamping bolt or other fastenerdisposed in central area of the upper and lower elongated spring leafs.The clamping bolt joins the upper and lower elongated spring leafs toeach other. In accordance with the invention, there is provided a slotarranged in the vicinity of an end of the upper elongated spring leaf. Aprotuberance that is formed near an end of the lower elongated springleaf is formed of a portion of the lower elongated spring leaf itselfThe protuberance is defined by a cut in the lower elongated spring leafand the material defined thereby is bent so as to be directedsubstantially orthogonal to a surface of the lower elongated springleaf. The protuberance is disposed to be accommodated within the slot ofthe upper elongated spring leaf so as to prevent lateral displacement ofthe upper and lower elongated spring leafs with respect to each other.

In one embodiment of this first aspect of the invention, there isprovided an insert that is disposed between the slot and theprotuberance for avoiding impact and squeaking noises. The insert may beformed of a polymeric material, such as nylon, Teflon®, polyethylene,and polyurethane.

In other embodiments of the invention, the protuberance and/or the slotis configured in a variety of selectable shapes, depending upon the usethat is made of the suspension spring arrangement. For example, the slotand protuberance may be configured to have square, rectangular, and/orcircular configurations.

In accordance with a further apparatus aspect of the invention, there isprovided a suspension spring arrangement for a vehicle, the suspensionspring arrangement being of the type having an upper elongated springleaf, a lower elongated spring leaf, and a clamping bolt disposed in acentral area of the upper and lower elongated spring leafs, whereby suchspring leafs are joined to one another. In accordance with the furtheraspect of the invention, there is provided a first slot disposed near afirst end of the upper elongated spring leaf, and a second slot disposednear a second end of the same spring leaf. A first protuberance isformed near a first end of a lower elongated spring leaf, the firstprotuberance being formed of a first portion of the lower elongatedspring leaf that is defined by a first cut and a corresponding portionthereof is directed substantially orthogonal to the lower elongatedspring leaf. Similarly, a second protuberance is formed near a secondend of the lower elongated spring leaf. When the upper and lowerelongated spring leafs are joined to one another, the first protuberanceis disposed to be accommodated within the first slot of the upperelongated spring leaf Similarly, in other embodiments, the secondprotuberance is accommodated within the second slot of the upperelongated spring leaf.

In one embodiment of this further aspect of the invention, there isprovided a first insert disposed between the first slot and the firstprotuberance. As previously noted, such an insert eliminates impact andsqueaking noises between the first slot and the first protuberance. Insimilar manner, a second insert is disposed between the second slot andthe second protuberance. Also, as previously noted, the first and secondslots, and the first and second protuberances, are configured inaccordance with selectable ones of square, rectangular, and circularshapes.

In accordance with a method aspect of the invention, there are providedthe steps of:

punching at least one slot near an end of a first spring leaf (12);

forming a protuberance near an end of a second spring leaf (14) byforming a partial cut and folding a portion of the second spring leaf(14) to be substantially orthogonal to the second spring leaf (14); and

joining the first and second spring leafs at respective central portionsthereof with a fastener whereby the protuberance of the second springleaf (14) is accommodated within the slot of the first spring leaf (12).In this manner, lateral displacement of the first and second springleafs with respect to each other is precluded.

In one embodiment of this method aspect of the invention, there isprovided the further step of installing an insert between theprotuberance of the second spring leaf and the slot of the first springleaf. In one embodiment, the installation of such an insert is performedbefore performing the step of joining the first and second spring leafsto one another.

BRIEF DESCRIPTION OF THE DRAWING

Comprehension of the invention is facilitated by reading the followingdetailed description, in conjunction with the annexed drawing, in which:

FIG. 1 is a side view of a known prior art automotive vehicle springassembly;

FIG. 2 is an enlarged view of a portion of the prior art spring assemblyof FIG. 1;

FIG. 3 is an enlarged view of a portion of the prior art spring assemblyof FIG. 1, specifically including a retaining clamp;

FIG. 4 is a perspective representation of a portion of the prior artspring assembly of FIG. 1 showing a retaining clamp;

FIG. 5 is a partially cross-sectional front view of a spring assemblyshowing a prior art retaining clamp that can be deployed in place on thespring assembly;

FIG. 6 is a perspective representation of a spring assembly constructedin accordance with the principles of the invention;

FIG. 7 is a plan view of a portion of the spring assembly of FIG. 6;

FIG. 8 is an underside plan view of a section of the spring assembly ofthe present invention; and

FIG. 9 is a side view of a portion of the spring assembly of the presentinvention showing a schematic illustration of an insert interposedbetween the slot and the protuberance.

DETAILED DESCRIPTION

FIG. 1 is side representation of a prior art spring assembly 10 for usein automotive vehicle suspension systems (not shown). As shown, there isprovided an elongated spring leaf 12, a lower elongated spring leaf 14,and a rivet 16 at the center of spring leafs 12 and 14. The clamp rivetmaintains the spring leafs joined to one another.

FIG. 2 is an enlarged view of a portion of the known spring assembly 10of FIG. 1, showing the lateral displacement between spring leafs 12 and14 that occurs during the use of the vehicle (not shown).

FIG. 3 is a plan view of the known arrangement shown in FIG. 2, furthershowing a retaining clamp 20 that prevents lateral or pivotaldisplacement between spring leafs 12 and 14.

FIG. 4 is an enlarged perspective representation of a spring leafassembly, specifically spring leaf assembly 10, wherein retaining clamp20, as previously described hereinabove with respect to FIG. 3,maintains elongated spring leafs 12 and 14 in parallel relation to oneanother. In this manner, the retaining clamp, precludes displacement ofthe spring leafs with respect to one another, in the manner describedhereinabove with respect to FIG. 2.

FIG. 5 is a partially cross-sectional representation that is useful todescribe the installation process of retaining clamp 20 on elongatedspring leafs 12 and 14. As shown in this figure, the retaining clampcommunicates with spring leaf 14 and is fixed thereto by a rivet 18.Initially, lateral walls 15 and 16 of retaining clamp 20 are arranged inan open position, and once the retaining clamp is secured to spring leaf14, walls 15 and 16 are closed in the direction shown by the arrows bythe use of a press (not shown) or a mallet (not shown).

FIGS. 6-9 illustrate a spring section constructed in accordance with theinvention. More specifically, it is evident from the figures that thearrangement of the invention does not employ a retaining clamp, such asretaining clamp 20 described hereinabove. FIG. 6 shows a preferredembodiment of the invention wherein there is provided a slot 22 near oneend of spring leaf 12. In this embodiment, a section 30 (FIG. 9) ofspring leaf 14 is cut and folded upward near one of the ends of springleaf 14 so as to produce an upward protuberance 24. The upwardprotuberance is accommodated within slot 22 of spring leaf 12 and servesto prevent lateral displacement between spring leafs 12 and 14. In thismanner, spring leafs 12 and 14 are maintained substantially fixed inlateral and pivotal relation to one another. An upward bend 32 ofsection 30 is shown in FIG. 9.

In the practice of this specific illustrative embodiment of theinvention, the length of slot 22 along the axial direction of springleaf 12 is determined by the separation distance between spring leafs 12and 14, which inter-spring leaf distance is determined in response tothe designed suspension travel of the vehicle. The width of slot 22 isdetermined in response to the expected lateral load. In addition, indetermining the length and width of the slot, consideration should begiven to combined and accumulated design tolerances to facilitateassembly of the spring and to minimize impact forces.

In accordance with a second aspect of the invention, spring leaf 10 isprovided with a slot 22 and protuberance 24 at each of its ends.

In accordance with a still further aspect of the invention, there isprovided a method of manufacturing and assembling a leaf springarrangement for a vehicle. The method includes the steps of:

punching one or two slots at respective ends of spring leaf 12 of springleaf assembly 10;

making a corresponding number of partial cuts near the ends of springleaf 14 so as to permit same to be folded along one or two edges in anupward direction;

joining spring leafs 12 and 14 at the central region with a rivet orlike fastening arrangement whereby such a protuberance 24 from springleaf 14 is disposed within one of the slots through spring leaf 12;

whereupon, lateral displacement of spring leafs 12 and 14 relative toone another is avoided.

In accordance with a further embodiment of the invention, there may beprovided one or more inserts, such as insert 31 (shown schematically inFIG. 9), formed of materials such as nylon, Teflon®, polyethylene,polyurethane, etc. between slot 22 and protuberance 24. Such insertswould reduce the effects of pounding between spring leafs 12 and 14, aswell as reducing squeaking.

In addition to the foregoing, it is within the scope of the presentinvention that slot 22 and protuberance 24 may be configured to havedifferent shapes than those presented herein. Such alternative shapeswould be responsive to the use to which the spring assembly is applied.More specifically, the protuberance can be configured to be square,rectangular, circular, or any other appropriate configuration, and thecorresponding slot would be configured to accommodate therein such aprotuberance.

Although the invention has been described in terms of specificembodiments and applications, persons skilled in the art can, in lightof this teaching, generate additional embodiments without exceeding thescope or departing from the spirit of the claimed invention.Accordingly, it is to be understood that the drawing and description inthis disclosure are proffered to facilitate comprehension of theinvention, and should not be construed to limit the scope thereof.

What is claimed is:
 1. A suspension spring arrangement for a vehicle,the suspension spring arrangement having an upper elongated spring leaf(12) and a lower elongated spring leaf (14), the suspension springarrangement comprising: a clamping bolt disposed in a central area ofthe upper elongated spring leaf (12) and the lower elongated spring leaf(14) to join the upper and lower elongated spring leaves to each other;a slot (22) disposed between the central area and an end of the upperelongated spring leaf (12); and a protuberance (24) formed between thecentral area and an end of the lower elongated spring leaf (14), saidprotuberance being formed of a portion of lower elongated spring leaf(14) that is defined by a cut and directed substantially orthogonal tothe lower elongated spring leaf (14); wherein the protuberance (24) isdisposed to be accommodated within the slot (22) of upper elongatedspring leaf (12) for preventing lateral displacement, and permittinglongitudinal displacement, of the upper and lower elongated springleaves with respect to each other.
 2. The suspension spring arrangementof claim 1, wherein there is further provided an insert disposed betweensaid slot (22) and said protuberance (24) for avoiding impact andsqueaking noises between said slot and said protuberance.
 3. Thesuspension spring arrangement of claim 1, wherein said slot (22) andsaid protuberance (24) are configured in accordance with selectable onesof square, rectangular, and circular configurations.
 4. A suspensionspring arrangement for a vehicle, the suspension spring arrangementhaving an upper elongated spring leaf (12), and a lower elongated springleaf (14), the suspension spring arrangement comprising: a clamping boltdisposed in a central area of the upper elongated spring leaf (12) andthe lower elongated spring leaf (14) to join the upper and lowerelongated spring leaves to each other; a first slot (22) disposedbetween the central area and a first end of the upper elongated springleaf (12); a second slot disposed between the central area and a secondend of the upper elongated spring leaf (12); a first protuberance (24)formed between the central area and a first end of a lower elongatedspring leaf (14), said first protuberance being formed of a firstportion of the lower elongated spring leaf (14) that is defined by afirst cut and directed substantially orthogonal to the lower elongatedspring leaf (14); and a second protuberance formed between the centralarea and a second end of the lower elongated spring leaf (14), saidsecond protuberance being formed of a second portion of lower elongatedspring leaf (14) that is defined by a second cut and directedsubstantially orthogonal to the lower elongated spring leaf (14);wherein said first protuberance (24) is disposed to be accommodatedwithin said first slot (22) of upper elongated spring leaf (12) forpreventing lateral displacement, and permitting longitudinaldisplacement, of the upper and lower elongated spring leaves withrespect to each other.
 5. The suspension spring arrangement of claim 4,wherein there are further provided: a first insert disposed between saidfirst slot (22) and said first protuberance (24) for avoiding impact andsqueaking noises between said first slot (22) and said firstprotuberance (24); and a second insert disposed between said second slot(22) and said second protuberance (24) for avoiding impact and squeakingnoises between said second slot (22) and said second protuberance. 6.The suspension spring arrangement of claim 4, wherein said first andsecond slots and said first and second protuberances are configured inaccordance with selectable ones of square, rectangular, and circularconfigurations.
 7. A method of manufacturing and assembling a suspensionspring for a vehicle, the method comprising the steps of: punching atleast one slot between a central region and an end of a first springleaf (12); forming a protuberance between a central region and an end ofa second spring leaf (14) by forming a partial cut and folding a portionof the second spring leaf (14) to be substantially orthogonal to thesecond spring leaf (14); and joining the first and second spring leavesat the respective central regions thereof with a fastener, whereby theprotuberance of the second spring leaf (14) is accommodated within theslot of the first spring leaf (12); whereby lateral displacement of thefirst and second spring leaves with respect to each other is precluded,and longitudinal displacement of the first and second spring leaves withrespect to each other is permitted.
 8. The method of claim 7, whereinthere is further provided the step of installing an insert between theprotuberance of the second spring leaf (14) and the slot of the firstspring leaf (12).
 9. The method of claim 8, wherein said step ofinstalling is performed before performing said step of joining.